C. A. Hogan wrote:

I've been reading the news letter on cooling.  Long years ago I flew
the F8F1 Grumman Bearcat.  The engine used the exhaust stacks as an
augmenter in the cooling air outlet.  Except for take off and very
high power settings the cowl flaps remained closed, I realize this
engine develops a little more power and had a higher displacement
R2800 34W.  Your P51 didn't have a prayer below 15000'.  Why can't the
same set up be used to help cool the mazda?   A spray paint gun uses
air to pull paint into the nozzle and my handy sandblaster even pulls
sand to the nozzle.  Is this possibility being over looked or is it
too small to be helpful?

Heck I think the Bearcat was better overall than a P51.
If it was available earlier in the war I think things
would have been different. If they put a turbocharger
on it like the P47 I think it would be even better
at high altitude. Rare Bear smokes off the P51's
when it is running right. Range? I don't know.

The ugly truth of the matter is the volume of an aircooled
engine is less then the volume of a liquid cooled engine,
a PSRU and a radiator. All other things being equal. 
The Ross PSRU currently used could be made smaller.

We have one thing going for us on the other hand. The 
rotary is very small for it's power out. Even compared 
to a comparable air cooled engine.

Given that handicap we need to find a way of stuffing
the rad under the cowl, tuning the exhaust system AND 
using the exhaust system as an augmenter. IMHO
too difficult compared to a P51 style duct.

I don't think people would accept the exhaust coming 
out the side of the cowl as was commonly done with
WW II fighter planes. Another problem we have which 
WW II fighter planes did not have and that is
too much noise.

A fourth problem we have is; we cannot afford to build
a custom radiator and test it in a wind tunnel. We
must use what we can buy off the shelf.

The designers of the air cooled radial engine fighter 
plane had a much easier time of it. 

Paul Lamar
 
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